Bridging plug



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y 13,1941- L. SPENCER BRIDGING PLUG Filed Feb 12, 1940 I INVENTOR A IMJT Z a Patented May 13, 1941 BRIDGING PLUG Lloyd Spencer, Los Angeles,Calif., assignor to Lane-Wells Company, Los Angeles, Calii'., acorporation of Delaware Application February 12, 1940, Serial No.318,519

'r'olaims. (01. 166-13) My invention relates to bridging plugs for oilwells, and among the objects of my invention are:

First, to provide a bridging plug having a resilient packing sleevewhich is held under tension while the bridging plug is lowered intoposition,

thereby reducing the diameter of the packing sleeve to increase thecirculation area between the bridging plug and the surrounding casingand facilitatemovement of the bridging plug in the well; I

Second, to provide a bridging plug wherein locking slips are cast in theends of the packing sleeve so that the packing sleeve serves to hold andguide thesllps in position; and the slips provide means whereby thepacking sleeve may be placed under tension;

. Third, to provide a bridging plug of this character which incorporatesa novel slip and packing sleeve arrangement in which the slips serve asan abutment to prevent axial flow of the packing sleeve between the,well casing and bridging plug under conditions of extreme heat andpressure; and

Fourth, to provide a bridging plug of this character which isparticularly adapted for use in conjunction with a setting tooldescribed in copending\application, Serial No. 308,608, filed December11, 1939, thereby providing a bridging plug which may be suspended froma cable.

With e above and other objects in view, as may appear hereinafter,reference is directed to the accompanying drawing, in which:

Figure 1 is an elevational view of my bridging plug with the parts inthe position assumed when the plug is being lowered into a well bore, aportion of the packing sleeve beingbroken away to facilitate theillustration;

Figure 2 is a similar elevational view of my bridging plug with theparts'shown in the posi-' tion assumed when the plug isset within acasing, said casing being shown in section and fragmentarily; Y

Figure} is an enlarged transversesectionalview through 3-4 of Figure 1with the packing sleeve partially removed to show the position of theslips;

Figure 4 is a similar transverse sectional view assumed when the plug isbeing lowered into the well; and Figure 6 isv a similar longitudinelsectional view showing the parts in the positions assumed when thebridging lug is seated.

My bridging plugi cludes a body I comprisin atubular portion 2 ofuniform diameter, the

- coaction with each cone.

lower end of which is connected to or joined integrally with a conicalportion 3. The conical portion is closed at its lower or larger end. Asliding cone 4 is mounted on the tubular portion 2 and the sloping lacesof the two cones 3 and 4 confront each other. The tubular portion 2 isprovided with wickers 5 which, when the sliding cone is moveddownwardly, are engaged by locking rings Gset in annular groovesprovided in the sliding cone, so as to prevent return movement of thesliding cone. In addition, a sealing ring 1- may be provided between thesliding cone and The two cones are adapted to coact with main slips 8and bridging slips 9. In the drawing four main slips and four bridgingslips are shown in The slips 8 and 9 are in the form of cylindricalsegments, the main slips 8 being somewhat larger than the bridging slipsand shaped to fit higher on their respective cones.

Anchor tongues Ill extend from the main slips between the bridgingslips, and anchor tongues ll extend from the bridging slips. The anchortongues are adapted to be molded into the ends of a packing sleeve I3which initially fits around the tubular portion 2, covers the anchortongues Ill and II and fills the spaces between the bridging slips 9.The anchor tongues II) are provided with side lugs l2 which are adapted,when the slips are in their initial or retracted position, to engage theaxially inner corners of the bridging slips 9, so thatthe main slipscannot move upwardly on the cone-without the bridging slips following.

The main slips have extending axially therefrom strap hooks ll whichride in and hook in- I taken through 4-4 of Figure 2, likewise with tlgp a D5) to the inner ends of slots [5 and It provided in the moving cone4 and the conical portion3, respectively. The strap hooks I4 hold theslips in position so that when the moving cone is moved upwardly awayfrom the conical portion 3 the sleeve I! may be placed under tension.The packing sleeve may have an initial diameter such as shown by dottedlines in Figure 5, and may be stretched so that its diameter is reducedto the solid line position in Figure 5 and the position shown in Figure1.,

- Inv order to facilitate fluid-tight seal between the packing-elementand the outside casing, as g as.the packing sleeve and the b ody oi theresponding set of slips during the initial setting movement of thebridging plug, as will be described hereinafter.

It is intended .that my bridging plug be used with thesetting tooldescribed in the hereinbefore-mentioned patent application. For thispurpose the upper end of the sliding cone l is provided with a channel2| and holes 22 are provided in the upper end of the tubular portion 2,which holes align with the channel whenthe packing sleeve has beenstretched a predetermined amount. Key balls 23 fit in the holes 22 andbear against the edge of the channel 2 i. The key balls coact and formpart of the setting tool hereinbefore mentioned.

Operation of my bridging plug is as follows:

The parts of the bridging plug are initially set in the positions asshown in Figures 1 and 5, that is, the packing sleeve l3 is placed undertension so that its diameter is reduced to the nominal diameter of thebridging plug when the parts *are held by the setting tool with whichthe bridging plug is lowered.

When the. bridging plug has been lowered to positionv the setting toolis actuated, which allows the key balls 23 to move inwardly, freeing thesliding cone 4. A spring, not shown but con-' stituting part of thesetting tool, forces the sliding cone 4 downwardly while other parts ofthe setting tool pull upwardly on the body I, so that the two cones aremoved toward each other:

.This movement-of the cones causes the slips to a ride up their conicalfaces and engage the surrounding casing. By reason of the shear pin 20one set of slips moves into locking position before the pins shear; thispermitsthe other set of slips to compress the packing element until in asealing position, such as is shown in Figure 6, before the pins shear.The second set of slips then move up their cone by reason of the forceexerted by the compressed packing sleeve, and at the same time the coneis wedgedfurther into the sleeve.

By reason of the fact that the packing "sleeve is initially undertension, a minimum of force is.

required to move it into a packing position, initial movement beingaided by the resiliency of the material constituting the packing sleeve.The

I packing sleeve is formed of rubber, synthetic rubparts of the bridgingplug. This is prevented by reason of the bridging slips 9 which,together bridging plug, the-edges of the slips which conwith the mainslips, form a complete ring against which the packing sleeve shirts.

By reason of the fact that the packing sleeve is under tension when thebridging plug is being lowered andpartly fills the space between thebridging plu'g and the casing when in its normal position, the clearancewhen running in may be maximum so that adequate circulation may be 7 hadaround the bridging plug to permit rapid movement of the plug throughthe well liquid therein.

Various changes and alternate arrangements may be made within the scopeof the appended claims, in which it is my intention to claim all noveltyinherent in the invention as broadly as the-prior art permits.

I claim: M

l. A bridging plug for wells comprising: a yieldable tubular packingsleeve adapted, when stretched, to reduce its diameter; means forholding said packing sleeve in a stretched condition while lowering saidsleeve into a well bore; means for releasing said sleeve; and means fordeforming said sleeve by axial compression and radial expansion beyondits normal condition.

2. A bridging plug .for wells comprising: a mandrel; coacting wedgingcones thereon adapted to be moved toward each other; a deformablepacking sleeve between said cones; and sets of wedging slips molded inthe 'ends of said sleeve and adapted to ride upon said cones, saidwedging slips arcuately overlapping each other to form an annularabutment for each end of said sleeve,

3. A bridging plug for wells comprising: a pair of confronting wedgingcones; coacting sets of slips for said cones adapted to engage asurrounding casing; a deformable packing sleeve mounted between saidsets of slips and attached thereto; and means for exerting a tensionalload on said packing sleeve tending to reduce the diameter thereof.

4. A bridging plug comprising: a deformable packing sleeve; wedgingslips molded in the ends of said sleeve and circumferentiallyoverlapping each other to form a continuous abutment for the ends'ofsaid sleeve; cone elements adapted to spread said slips into engagementwith a surrounding casing; means initially connecting said slips to saidcone elements; and means for holding said cone elements in an axiallyseparated position wherein said sleeve is under tension.

5. A bridging plug, as set forth in claim 4, wherein said cones andslips are relatively movable to place said packing-sleeve under axialcompression and radial expansion against a surrounding casing, and saidpacking sleeve has intermediate normal dimensions.

6. A bridging plug as recited in claim 2 wherein the ends of said slipsabutting said sleeve are shaped to mold radially inner and radiallyouter pressure lips on said sleeve.

'7. Abridging plug as recited in claim 4 where- .in the ends of saidslips abutting said sleeve are LLOYD SPENCER.

